Dealing with Logs and Natural Logs

This problem is giving me some trouble.

"Raising a musical note one octave has the effect of doubling the pitch, or frequency, of the sound. You do not perceive the note to sound “twice as high” as you might expect. Perceived pitch is given by the function , where P is the perceived pitch in mels, and f is the frequency in hertz. Let frequency vary in value from 10 to 100,000 hertz and let perceived pitch vary from 0 to 6000 mels. Graph this equation in your calculator." I am confused how to graph this and if I am putting the right equation in my calculator.

"Use the graph to find the perceived pitch P for a frequency of 10,000 hertz. Explain how this value is obtained."

"'Determine the perceived pitch P for a frequency of 10,000 hertz algebraically."

"Use your graph to find the frequency f that gives a perceived pitch of 1500 mels. Explain how this value is obtained."